In 1972, Aretha Franklin performed a set of gospel songs inside a Los Angeles church that eventually became Amazing Grace—the biggest-selling album of her career. But Franklin wasn’t the only person recording that day. The late director Sydney Pollack took behind-the-scenes footage of Franklin’s show, and IndieWire is reporting that it’s about to be seen publicly for the first time.

Varietywrote about the existence of the Pollack’s recordings in 2010—two years after his death:

More than 20 hours of 16mm footage—vaulted away for 38 years—are now being edited into a concert film that Warner Bros. once envisioned (curiously, in retrospect) as part of a double bill with “Superfly.”

“We’re working off Sydney’s notes,” says [producer Alan Elliot], who acquired the project from Warner Bros. at Pollack’s urging and hired Pollack’s longtime editor William Steinkamp (“Out of Africa”) to help shape it into a film for possible theatrical distribution.

Five years later (and 43 years after it was filmed), and Amazing Grace finally has its first trailer. It premieres next month at the Toronto International Film Festival.